Iraqi Shiite men chant slogans during a demonstration to support the Iraqi forces in Najaf, Iraq. / Khider Abbas, European Pressphoto Agency

by Jim Michaels, USA TODAY

by Jim Michaels, USA TODAY

"I don't want to be rocking on my front porch when I'm retired and read about Iraq as yet another foreign policy failure," Marine Col. John Coleman told me, jabbing his finger in the air for emphasis.

The implication: This wasn't going to be another Vietnam.

It was 2004, and we were at Camp Fallujah, a large military base west of Baghdad. It was an uncertain time in Iraq. The U.S.-led invasion had deposed Saddam Hussein, and the full-blown insurgency hadn't yet emerged.

No one knew what to expect. There were as many hopeful signs - new cars and air conditioners flooding into Baghdad - as there were ominous signs, such as car bombs and the killing of contractors in Fallujah.

Coleman, now retired, was talking about the need to stay the course. The fight wasn't over yet. The United States couldn't afford another loss.

The colonel is too young to be rocking on his front porch. But the images last week of black-clad militants rampaging through Mosul, Iraq's second-largest city, and edging toward Baghdad are already drawing comparisons to the iconic image of U.S. impotence: helicopters pulling desperate Americans out of the Saigon in advance of the North Vietnamese invasion.

I've been back to Iraq more than a dozen times since the U.S.-led invasion, watching the initial hope in 2003 turn to despair by 2006, when a civil war raged through Baghdad and other parts of the country. The surge in 2007, however, brought the country back from the brink. By the time the last U.S. forces left in 2011, Iraq was relatively peaceful. Hope had returned.

Is Iraq lost?

In 2007, I visited one of the first outposts established as part of the surge of U.S. forces that was designed to reverse the downward spiral of the war.

Then-Army Capt. Erik Peterson was holed up in a small compound ringed by a massive blast wall. Gunfire crackled through the night. Every week, about 30 to 40 bodies would be uncovered in his sector, a neighborhood called Ghazaliyah, as a result of sectarian bloodshed.

The neighborhood was evenly split between Sunnis and Shiites. Peterson positioned his outpost right on the fault line between the warring factions. The 220 American and Iraqi soldiers slowly began establishing order. They served as cops and adjudicated disputes.

It was dangerous and exhausting work. By the time his unit departed about a year later, violence was down. There were fewer bodies in the street. Some semblance of order had returned.

The security had come at a tremendous cost. More than 4,000 Americans died during the Iraq war, many of them when U.S. forces surged into Baghdad and other areas in 2007, leaving the safety of large bases and moving into neighborhoods.

Peterson, now a major at Fort Riley, Kan., is watching events closely. I expected to hear pessimism. The gains he fought so hard for seemed to be unraveling.

What I heard instead was a long view rare among Americans. Somehow, Iraqis have always pulled themselves back from the brink, he said.

It's a perspective borne of years of fighting in an ambiguous, confusing environment. "We can only impose our will so long," he said.

He added, "I remember getting into Baghdad in '06 thinking we lost the war."

In 2004, he was in the southern city of Najaf when Shiites took to the streets, battling U.S. forces in chaotic scenes that threatened to tear the country apart. It didn't, and Iraqis reached enough of a compromise to stave off disaster.

"I am not a defeatist yet," Peterson said. And, he might add, it may be too early to call Iraq a failure.

Michaels, a former Marine infantry officer, covers military affairs for USA TODAY.